Apparatus for internally sterilizing flexible tubing with ultraviolet radiation



United States Patent APPARATUS FOR INTERNALLY STERILIZING FLEXIBLE TUBING WITH ULTRAVIOLET RADIATION 250/51 1 [51] Int.Cl. ..G0ln2l/00 [50] FieldofSearch 250/5l,52

[56] References Cited UNITED STATES PATENTS 2,194,463 3/1940 Powley 250/52 Primary Examiner-William F. Lindquist a Attorneys-Emory L. Groff and Emory L. Groff, Jr.

ABSTRACT: Apparatus for producing internally sterilized tubing by placing the tubing over an ultraviolet ray emitting tube for a period of time sufficient to sterilize the inside of the 5 Claims, 6 Drawing Figs. tubing and then rem the ing.

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5' 20 3 l'l-llllllllll n 29 39 2 u 1 III n S 2 55 45 I I 3.8 5 n '6 3.6 3'7 M 5 l6 +-s l0 I i is 35 N 2x d PATENTED 05022 I970 SHEET 2 BF 3 1 v APPARATUS FOR INTERNALLY STERILIZING FLEXIBLE TUBING WITH ULTRAVIOLET RADIATION This invention has been devised to provide a method and apparatus for internally sterilizing tubing'such as opaque bellows type tubing as used in hospitals particularly on anesthetic administering equipment.

Presently the sterilization of porous tubing is achieved by means of gas, usually ethylene oxide gas. Sterilization by this means however takes approximately 48 hours as the tubing after sterilization has to be degassed. In the case of nonporous tubing e.g. stainless steel sterilization is achieved in an autoclave which takes approximately 30 minutes.

By using the method and apparatus of the invention tubing can be sterilized in a fraction of the time required hitherto and is immediately available for reuse.

The method of this invention comprises drawing the tubing onto an ultraviolet ray emitting tube, energizing the ultraviolet ray tube, maintaining the tubing on the energized ultraviolet ray tube for a period of time sufficient to sterilize the interior of the tubing and then withdrawing the; tubing from the ultraviolet ray tube.

The apparatus for carrying out the method comprises an ultraviolet ray emitting tube, means to support the ultraviolet tube by one end, movable means tosupport the tubing during the placement of the tubing on the ultraviolet tube whilst thereon and during withdrawal therefrom and means connectable to the ultraviolet tube forfcornpleting an electric circuit enabling said ultraviolet tube to be illuminated.

A preferred embodiment of the invention as applied to the sterilization of opaque flexiblebellows type tubing is illus trated in the accompanying drawings in which:

FIG. 1 is an exploded perspective view of the component parts of the apparatus and the control panel therefor;

.FIG. 2 is a side elevation showing operative components of the apparatus in section and a tubing to'be sterilized, the apparatus being shown inclined as might bedesirable in particular locations for use; i a

FIG. 3 is a plan viewpartly in section with the tubing in sterilizing position;

FIG. 4 is an enlarged fragmentary side viewin section on the FIG. 5 is an enlarged end elevation in section on the line 5-5 ofFIG. 2; and

FIG. 6 is a circuit diagram for the electrical components of the apparatus.

As illustrated the apparatus comprises a hollow base member 10 of rectangular cross-sectional configuration supported on legs 11 which rest on a bench 12. Two spaced parallel bars 13 are securedto the upper surface of the base 10 to form a trough 14 between the bars.

One end 15 of an ultraviolet rayemittingtube 16 is supported within the end 17 of the trough 14 so that the tube extends approximately halfway along the length of the trough 14, the tube 16 is spaced from the walls and floor of the trough 14. The tube 16 is supported near one end in a flexible bush 18 which is fixed in adjustablefashion to the bars 13 by a clamp plate 19.

A tubing carrier 20 of tubular configuration is dimensioned to slide freely in the trough l4 and over the ultraviolet tube 16. The top part of the periphery of the carrier 20 is cut away for the greater part of its length to form a compartment 21 where in tubing 22 to be sterilized can be accommodated. The carrier 20 is retained in the trough 14 by two keeper plates 23 which are secured to the bars 13 so that the keeper plates project slightly into the trough 14 to contact the longitudinal compartment edges 24 of the carrier 20. p

A bush 25 made of or coated on its bore with nylon is ,mounted in the fully circular end 26 of the carrier 20 to prevent surface damage to the glass case of the ultraviolet ray tube. The bore of the bush 25 is a sliding fit on the tube 16 so that the tube 16 is always supported as the carrier 26) is moved in the trough 14. It will be seen from FIG. 2 that the tube 16 can be supported in alignment with butclear of the compartment 21 enabling the tubing 22 to be loaded into the compartment 21. From FIG. 5 it will be seen that the compartment 21 is slightly greater than a semicircle in cross section to retain the tubing 22 in the compartment 21. Desirably the inner surfaces of the compartment are coated with a material e.g. nylon which will provide: I

(a) an easily clearable surface,

(b) a partially resilient surface, and

(c) a surface which will provide a frictional grip on the tubing to be sterilized.

Two circlips 29 are mounted adjacent the ends of compart ment 21 to engage in corrugations 3t) in the tubing 22 and prevent longitudinal displacement thereof.

A bar 32 and handle 33 are secured to the end 34 of the carrier 20. By means of the handle 33-the carrier 20 can be slid along the trough 14 so that tubing in compartment 21 will pass over the ultraviolet ray tube 16. The end 26.0f the carrier 20 engages and compresses a spring buffer 35 before engaging abutment 37 which determines the tubing sterilizing position.

Electrically there is provided a spring'loaded contact 38 in a housing depending from the bar 32 and located in the end 34 of the carrier 20 so as to engage the end 27 of the tube 16 when the carrier positions the tubin'g22 in the sterilizing position as shown in FIG. 3.

An electrical contact pin 39 mounted near one end of the bar 32 is electrically connected internally of bar 32 as at 40 with the contact 38. With the carrier 20 in the position shown in FIG. 4, the contact pin 39 engages a fixed contact 41 secured to the base 10. The other end of the tube 16 is permanently connected as at 42 to a junction. box 43.

A micro switch 44 is securedto one bar 13 and is actuated by a pin 45 on the end 26 of the carrier 20 when it is in the position shown in FIG. 3.

An electrical control panel 46 is associated with the apparatus. The panel 46 carries a transformer 47, a current sensitive relay 48, a synchronous timer 49, an isolating switch 50 and two indicator lights 51 and 52. When the micro switch 47 is closed by the pin 45, the tube transformer 47 is energized so that the tube l6ignites. At the same time the flow of current to the tube operates the relay. 48 to energize the timer 49..The

timer 49 energizes asolenoid 53"which is mounted beneath the base 10. The armature 54 of said solenoid rises to engage a hole 55 in the underside of the carrier 20 near its end 34. The carrier is thus locked in position with the tube 16 ignited. While the tube 16 is ignited the indicator light 51 is energized. When the timer 49 reaches the end of its cycle the solenoid 53 is deenergized so that its armature drops and releases the carrier 20, an assistance spring may be incorporated to ensure the release of the armature from the carrier. The spring 35 pushes the carrier a short distance along the trough 14 so that the switch 44 is disengaged from pin 45 thus deenergizing the tube 16. The operator can now withdrawthe carrier to the position shown in FIG. 2, and the tubing 22 can be removed.

The light 51 shows only when the tube 16 is illuminated and the light 52 is illuminated when the timer reaches the end of its time cycle and is extinguished when the switch 44 is operated to reilluminate the tube 16.

The electrical conduits which are necessarily associated with the apparatus have not been shown in FIGS. 1 to 5, but it is to be understood that they can be readily accommodated in the hollow interior of the base 10.

The sterilizing cycle is determined by the nature of tubing and the circumstances under which the tubing has been previously used or stored. For tubing in current use it has been found that pathogenic organisms can be sterilized by an exposure to ultraviolet radiation for 20 seconds using the method and apparatus of this invention.

A cover 56 is adapted to shield the operator from ultraviolet rays when the tube 16 is ignited.

A removable ultraviolet sensitive indicator of the colour change type may be placed on the tubing before exposure so that a colour change on exposure to ultraviolet radiation will indicate that the tubing has undergone a sterilization cycle.

The foregoing description has been directed specifically to a carrier for flexible tubing. It will be appreciated that for use with rigid tubes modifications would have to be made at least to the shape of the compartment and the manner in which the tubing is held in place.

Iclaim:

1. Apparatus for internally sterilizing tubing, said apparatus comprising support means, an ultraviolet ray emitting tube mounted by one end on said support means, an ultraviolet ray tube energizing circuit electrically connected to said one end of said ultraviolet ray tube, slidably movable cradle means to support the tubing, guide means for said cradle means on said support means and disposed parallel to the axis of said ultraviolet ray tube and spaced therefrom to place tubing supported in the cradle means in substantially axial alignment with the ultraviolet ray tube, bearing means on the cradle means to provide lateral support for said ultraviolet ray tube, first terminal means on said support means electrically connected to said ultraviolet ray tube energizing circuit, second terminal means on said cradle means for electrically connecting and disconnecting the other end of said ultraviolet tube to said first terminal means at the completion and commencement respectively of inward and outward movements of the cradle means during which the tubing is slipped over and removed from said ultraviolet ray tube.

2. Apparatus as claimed in claim l including tubular cradle means, an elongated opening in the tubular cradle means formed by removing part of the periphery thereof to admit the tubing into the interior of the tubular cradle means and securing means on the cradle means to retain the tubing in the cradle means.

3. Apparatus as claimed in claim 2 for sterilizing flexible tubing wherein the internal diameter of the cradle means is substantially the same as the outside diameter of the flexible tubing and the elongated opening therein is formed by removing less than half of the circumference of said cradle means so that said opening is narrower than the outside diameter of the flexible tubing. the long edges of the opening constituting said securing means.

4. Apparatus as claimed in claim 2 including cradle retaining means on said guide means in sliding engagement with the long edges of the elongated opening in said cradle means.

5. Apparatus as claimed in claim 4 including an ultraviolet ray tube energizing circuit control switch operated by an actuator on said cradle means when the cradle means is at the end of its inward movement, timer means in said energizing circuit initiated by the actuation of said control switch and releasable cradle means movement preventing lock means mounted on said support means and actuated by said timer means. 

